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United States Patent | 5,538,634 |
Pfiffner ,   et al. | July 23, 1996 |
A solid phase extraction (SPE) filtration disk provides a glass fiber disk embedded with bonded silica/particulate chemistries homogeneously dispersed throughout the disk. Bonded silica/particulate chemistries are added to the glass fibers (and acidified water/solvent solution) during the formation of the glass fiber paper, as opposed to after the formation of the glass fiber paper. This enables homogenous dispersion of silica throughout the entire depth of the filtration disk.
Inventors: | Pfiffner; Tim E. (P.O. Box 6089, Santa Rosa, CA 95406); Shatkin; Steve M. (P.O. Box 6089, Santa Rosa, CA 95406) |
Appl. No.: | 430766 |
Filed: | April 27, 1995 |
Current U.S. Class: | 210/500.26; 210/198.3; 210/502.1; 210/505; 264/45.1; 264/257; 501/55 |
Intern'l Class: | B01D 039/00 |
Field of Search: | 210/500.26,505,502.1,198.3,500.25 501/39,53,55 264/42,45.1,257 |
Re32107 | Apr., 1986 | January | 501/55. |
3455818 | Jul., 1969 | Leifield | 210/502. |
3904422 | Sep., 1975 | Eaton | 501/39. |
4789479 | Dec., 1988 | Onitsuka et al. | 210/505. |
4971736 | Nov., 1990 | Hagen et al. | 264/41. |
5403489 | Apr., 1995 | Hagen et al. | 210/502. |